The long term objective of the proposed research is to learn how to effectively use cellular therapy in regenerative medicine, especially as pertains to dermatology. In particular, our goal is to convert the identity of skin at the stump site of amputees to thick palmo/plantar (volar) type skin to enhance their use of prosthetics. Towards this clinical goal we first will define the basic genetic control of volar fibroblast skin identity Then we will define homeostatic mechanisms whereby non-volar tissue retains its identity. In so doing, we will optimize conditions for our final effort to use autologous fibroblasts to induce ectopic volar skin in volunteers. We will fully excise this ectopic acral skin as a proof-of-concep trial and a prelude to clinical optimization and use in amputees.